Chiral Ferrocenyl Amino Alcohols Research Articles

Synthesis and crystal structure of chiral ferrocenyl amino alcohols for asymmetric transfer hydrogenation

Synthesis and crystal structure of chiral ferrocenyl amino alcohols for asymmetric transfer hydrogenation

Synthesis, Crystal Structure of Chiral Ferrocenyl Amino Alcohols, and Its Use for Asymmetric Transfer Hydrogenation

Two chiral ferrocenyl amino alcohols (IIIa and IIIb) have been synthesized for the iridium catalyzed asymmetric transfer hydrogenation of aromatic ketones. The structures of two chiral ferrocenyl amino alcohols have been determined by single crystal X-ray diffraction (CIF files CCDC nos. 1056737 (IIIa) and 1056734 (IIIb)). The results show that the activity and enantioselectivity of the chiral iridium catalyst are very sensitive to the substrate structure. Ir(I)-catalyzed asymmetric transfer hydrogenation of acetophenone resulted in moderate to good yield and lower enantioselectivity; asymmetric transfer hydrogenation of proopiophenone and 2-benzoylpyridine resulted in lower yield and lower enantioselectivity; as for 4-benzoylpyridine, good results have been achieved.

ChemInform Abstract: Synthesis of Chiral Ferrocenyl Amino Alcohols Involving a Diastereospecific Oxidation: Use in Asymmetric Catalysis.

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Catalytic Enantioselective Reduction of Prochiral Ketones with Chiral Ferrocenyl Amino Alcohols

AbstractThe asymmetric reduction of prochiral ketones was catalyzed by a class of recoverable and highly stable chiral ferrocenyl amino alcohols derived from natural amino acids to yield optically active secondary alcohols in high chemical yields and moderate to good enantiomeric excesses.

Chiral Ferrocenyl Amino Alcohols for Enantioselective Additions of Diethylzinc to Aldehydes.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Chiral ferrocenyl amino alcohols for enantioselective additions of diethylzinc to aldehydes

Optically active ferrocenyl amino alcohols have been prepared from commercially available l-alaninol, l-leucinol and l-valinol. They have been utilized as chiral ligands in the catalytic addition of diethylzinc to aldehydes. The influence of the substituents on the stereogenic centers of the ligand has been studied. Enantioselectivities up to 95% have been obtained.

Screening of Chiral Ferrocenyl Amino Alcohols as Ligands for Ruthenium‐Catalyzed Transfer Hydrogenation of Ketones.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Screening of chiral ferrocenyl amino alcohols as ligands for ruthenium-catalysed transfer hydrogenation of ketones

A variety of ferrocenyl amino alcohols possessing central chirality have been screened as ligands for ruthenium(II)-catalysed transfer hydrogenation of acetophenone using 2-propanol in the presence of KOH as the hydrogen source. Enantiomerically enriched 1-phenylethanol was obtained in high yield and 70% e.e. using ligand 9. This ligand was employed in the asymmetric reduction of different arylalkyl ketones and the corresponding alcohols were obtained in up to 80% e.e. A comparison of the catalytic properties of ferrocenyl amino alcohols and their phenyl analogues is discussed briefly.

Chiral Ferrocenyl Amino Alcohols: Preparation and Application as Catalysts in the Enantioselective Reduction of Ketones Using NaBH4/I2

AbstractFive novel chiral ferrocenyl amino alcohols were prepared from natural amino adds and used as catalysts in the asymmetric reduction of prochiral ketones with NaBH4/I2 combination. The incorporation of the ferrocenyl moiety into the molecule of the chiral amino alcohols greatly improved their enantioselectivity in the catalysis. The optically active secondary alcohols were obtained in moderate to good enantiomeric excesses and high chemical yields.

ChemInform Abstract: Chiral Ferrocenyl Amino Alcohols as Catalysts for the Enantioselective Borane Reduction of Ketones.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Chiral ferrocenyl amino alcohols as catalysts for the enantioselective borane reduction of ketones

The catalytic asymmetric borane reduction of prochiral ketones was examined in the presence of chiral oxazaborolidine catalysts prepared in situ from chiral ferrocenyl amino alcohols. The corresponding chiral secondary amino alcohols were obtained with modest to high enantiomeric excesses (up to 90%) using (1 S,2 S)-2-amino-1-ferrocenyl-3,3-dimethyl-1-butanol 5c.

ChemInform Abstract: Chiral Ferrocenyl Amino Alcohols as Analogues of Norephedrine Catalysts for Enantioselective Addition of Diethylzinc to Benzaldehyde.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Chiral ferrocenyl amino alcohols as analogues of norephedrine catalysts for enantioselective addition of diethylzinc to benzaldehyde

Optically active ferrocenyl amino alcohols have been prepared from commercially available l-alaninol and l-leucinol. They have been used in catalytic amounts as chiral ligands in the addition of diethylzinc to benzaldehyde. 1-Phenylpropanol has thus been obtained in up to 95% enantiomeric excess.

Synthesis of chiral ferrocenyl aminoalcohols involving a diastereospecific oxidation: use in asymmetric catalysis

The synthesis of six new chiral ferrocenic aminoalcohols has been performed. One step of this synthesis was a diastereospecific oxidation of diastereomeric mixtures of 1-[2-( N, N-dimethylaminomethyl)ferrocenyl]alcohols by manganese dioxide: one diastereomer was oxidized, while the other stayed inert. The six new chiral compounds in association with ZnEt 2 proved to be good catalysts in the asymmetric ethylation of benzaldehyde (77 to 88% ee).

Synthesis of new ferrocenyl aminoalcohols and aminonitriles and catalytic properties of the aminoalcohols in the ethylation of benzaldehyde

Chiral ferrocenyl aminoalcohols possessing either OH or NR 2 functionality α to the ferrocenyl ring were prepared and exhibit modest enantioselectivities for the addition of diethylzinc to benzaldehyde. Chiral ferrocenyl aminonitriles exhibit a facile inversion process in protonic solvents.

ChemInform Abstract: Enantioselective Addition of Dialkylzinc to Aldehydes Catalyzed by Chiral Ferrocenyl Amino Alcohols

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.